Broadband wireless networks based on various standards (e.g. Institute of Electronic and Electric Engineers (IEEE) 802.16 based WiMAX standard and its evolution to IEEE 802.16m provides various types of services such as voice, packet data and so on. In order to provide these kinds of services, control information and data packets needs to be exchanged between a transmitting device and a receiving device. In downlink scenario, the transmitting device may include a base station and the receiving device may include a mobile station. In uplink scenario, the transmitting device may include a mobile station and the receiving device may include a base station.
Typically, service data is generated by various applications running at the transmitting device for providing various types of services. The service data is then exchanged between the transmitting device and the receiving device upon establishing a connection. Generally, the connection is identified by a connection identifier.
Multiple connections may exist between the transmitting device and the receiving device to carry service user data belonging to multiple applications running at the transmitting device and the receiving device. On the contrary, a single connection may also be used to carry the service user data belonging to multiple applications running at the transmitting device and the receiving device. Each connection carries variable size MAC Service Data Units (SDUs) received from various applications and contains service user data.
Typically, the transmitting device generates MAC PDUs from MAC SDUs and transmits the MAC PDUs in physical burst to the receiving device over a wireless network. A MAC PDU generally consists of a MAC header and a payload. It is understood that, other headers or sub-headers may be present between the MAC header and the payload. If there are multiple MAC SDUs intended for the receiving device, the transmitting device packs multiple MAC SDUs of varying size in a payload of a MAC PDU. In existing technique, the transmitting device also packs fragmented MAC SDUs and unfragmented MAC SDUs of variable size in the same MAC PDU. Therefore, the transmitting device needs to include a variable size header in the MAC PDU so that the receiving device identifies number of MAC SDUs, length of each MAC SDU and status (i.e. whether the MAC SDU is fragmented or not) of each MAC SDU in the payload. Consequently, there is significant increase in processing time at the transmitting, device for generating the MAC PDU and at the receiving device for processing the MAC PDU.
Moreover, upon receiving the MAC PDU, the receiving device has to perform dual reassembly functions in case Automatic Repeat Request (ARQ) connection is enabled. The first reassembly function reassembles the fragmented ARQ blocks. The ARQ block consists of unfragmented MAC SDU(s) and/or fragmented MAC SDUs. The second reassembly function reassembles the fragmented MAC SDUs received in the ARQ block. This may result in increased processing time at the receiving device.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.